The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines combust an air/fuel (A/F) mixture within cylinders to drive pistons. The pistons rotatably turn a crankshaft generating drive torque. The drive torque may be transferred to a driveline of a vehicle (e.g., wheels) via a transmission. The drive torque may also be translated (i.e., multiplied) by one of a plurality of gear ratios of the transmission. The transmission may be coupled to the crankshaft via a torque converter (e.g., a fluid coupling).
The transmission may include valves (e.g., spring-loaded valves), clutches, and one or more planetary gear sets. The transmission may also include a check balls and/or servos. The servos may actuate one or more of the clutches, and the clutches may engage one or more gears of the planetary gear sets. The transmission includes hydraulic fluid that controls one or more components of the transmission. The hydraulic fluid is typically supplied to the transmission from a main pump in the torque converter.
The hydraulic fluid flows through one or more of the valves depending on a pressure of the hydraulic fluid (e.g., spring-loaded valves with different spring rates). Alternatively, the valves may be actuated by electro-mechanical servos that are controlled by an external controller. The hydraulic fluid may also actuate servos to engage one or more of the clutches. Furthermore, each of the clutches may correspond to a gear of the planetary gear sets. Thus, the hydraulic fluid may engage one or more gears of the planetary gear sets (via a combination of the servos and the clutches) to achieve a desired gear ratio.